Bump smoltcp from 0.11.0 to 0.12.0

Bumps [smoltcp](https://github.com/smoltcp-rs/smoltcp) from 0.11.0 to 0.12.0.
- [Release notes](https://github.com/smoltcp-rs/smoltcp/releases)
- [Changelog](https://github.com/smoltcp-rs/smoltcp/blob/main/CHANGELOG.md)
- [Commits](smoltcp-rs/smoltcp@v0.11.0...v0.12.0)

---
updated-dependencies:
- dependency-name: smoltcp
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Cargo.toml

@@ -36,7 +36,7 @@ rand = { version = "0.8.5", default-features = false }
 rand_hc = "0.3.1"
 raw-cpuid = "11.2.0"
 sha2 = { version = "0.10.8", default-features = false, features = ["force-soft"] }
-smoltcp = { version = "0.11.0", default-features = false, features = ["alloc", "medium-ethernet", "socket-tcp", "socket-udp", "socket-dhcpv4", "proto-ipv4", "proto-dhcpv4"] }
+smoltcp = { version = "0.12.0", default-features = false, features = ["alloc", "medium-ethernet", "socket-tcp", "socket-udp", "socket-dhcpv4", "proto-ipv4", "proto-dhcpv4"] }
 spin = "0.9.8"
 time = { version = "0.2.27", default-features = false }
 geodate = { version = "0.5.0", default-features = false }